Such devices which are intended to replace the bothersome manual rewinding of the hose after use are known. PCT Application WO 03/078797 for instance, discloses a reciprocating water piston motor which drives the reel. The same purpose is accomplished in U.S. Pat. Nos. 4,813,627 and 5,560,391, which use a spiral spring that is loaded upon unwinding. Similarly spring-loaded is a device disclosed by U.S. Pat. No. 6,488,224 that also features a hydraulic brake governor to maintain a more or less constant rewinding speed. U.S. Pat. No. 6,178,992 uses an electric motor as power source.
All these devices are, however, cumbersome, complex, expensive and, what is most important, unsafe.